A switching system is a key component of a packet switching device. As shown in FIG. 1, the switching system includes a switching access apparatus and a switching apparatus. The switching access apparatus includes a source switching access apparatus and a destination switching access apparatus. The source switching apparatus divides a network message into cells, and forwards the cells to the destination switching access apparatus via the switching apparatus. The switching apparatus is constituted by the switching units connected to each other. High-speed serial links are used to connect the source switching access apparatus and one of the switching units, to connect every two switching units, and to connect one of the switching units and the destination switching access apparatus.
Data are transmitted in a switching network by using cells as units. The switching access apparatus dynamically establishes a routing table according to a real-time link state, and completes transmission of the cells by looking-up the routing table. Likewise, the switching apparatus will dynamically establish a routing table by monitoring a real-time link state, so as to complete correct forwarding of the cells. It can be thus seen that correct control over a link state according to different switching network environments plays an important role in improvement of the performance of the whole switching network.
However, with the increase of the capacity of the switching network increases, i.e., the increase of the number of switching access apparatuses and switching apparatuses in the switching network as well as the increase of the rates of high-speed serial links connected to each other, there are more and more factors influencing the states of the high-speed serial links. How to effectively control the link state will influence the performance of the whole switching network.
However, according to the link monitoring solution for an existing switching network, frequent link state hopping will happen in a boundary link, thus resulting in instability the routing table of the switching access apparatus or the switching apparatus, and influencing transmission of the cells.